[ThinLTO] Add FunctionAttrs to ThinLTO index

Adds function attributes to index: ReadNone, ReadOnly, NoRecurse, NoAlias. This attributes will be used for future ThinLTO optimizations that will propag

[ThinLTO] Add FunctionAttrs to ThinLTO index

Adds function attributes to index: ReadNone, ReadOnly, NoRecurse, NoAlias. This attributes will be used for future ThinLTO optimizations that will propagate function attributes across modules.

llvm-svn: 310061

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ThinLTO Minimized Bitcode File Size Reduction

Summary: Currently the ThinLTO minimized bitcode file only strip the debug info, but there is still a lot of information in the minimized bit code file

ThinLTO Minimized Bitcode File Size Reduction

Summary: Currently the ThinLTO minimized bitcode file only strip the debug info, but there is still a lot of information in the minimized bit code file that will be not used for thin linker. In this patch, most of the extra information is striped to reduce the minimized bitcode file. Now only ModuleVersion, ModuleInfo, ModuleGlobalValueSummary, ModuleHash, Symtab and Strtab are left. Now the minimized bitcode file size is reduced to 15%-30% of the debug info stripped bitcode file size.

Reviewers: danielcdh, tejohnson, pcc

Reviewed By: pcc

Subscribers: mehdi_amini, aprantl, inglorion, eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D35334

llvm-svn: 308760

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Debug Info: Add a file: field to DIImportedEntity.

DIImportedEntity has a line number, but not a file field. To determine
the decl_line/decl_file we combine the line number from the
DIImportedEntity

Debug Info: Add a file: field to DIImportedEntity.

DIImportedEntity has a line number, but not a file field. To determine
the decl_line/decl_file we combine the line number from the
DIImportedEntity with the file from the DIImportedEntity's scope. This
does not work correctly when the parent scope is a DINamespace or a
DIModule, both of which do not have a source file.

This patch adds a file field to DIImportedEntity to unambiguously
identify the source location of the using/import declaration. Most
testcase updates are mechanical, the interesting one is the removal of
the FIXME in test/DebugInfo/Generic/namespace.ll.

This fixes PR33822. See https://bugs.llvm.org/show_bug.cgi?id=33822
for more context.

<rdar://problem/33357889>
https://bugs.llvm.org/show_bug.cgi?id=33822

Differential Revision: https://reviews.llvm.org/D35583

llvm-svn: 308398

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Enhance synchscope representation

OpenCL 2.0 introduces the notion of memory scopes in atomic operations to
global and local memory. These scopes restrict how synchronization is
achieved, whic

Enhance synchscope representation

OpenCL 2.0 introduces the notion of memory scopes in atomic operations to
global and local memory. These scopes restrict how synchronization is
achieved, which can result in improved performance.

This change extends existing notion of synchronization scopes in LLVM to
support arbitrary scopes expressed as target-specific strings, in addition to
the already defined scopes (single thread, system).

The LLVM IR and MIR syntax for expressing synchronization scopes has changed
to use *syncscope("<scope>")*, where <scope> can be "singlethread" (this
replaces *singlethread* keyword), or a target-specific name. As before, if
the scope is not specified, it defaults to CrossThread/System scope.

Implementation details:
- Mapping from synchronization scope name/string to synchronization scope id
is stored in LLVM context;
- CrossThread/System and SingleThread scopes are pre-defined to efficiently
check for known scopes without comparing strings;
- Synchronization scope names are stored in SYNC_SCOPE_NAMES_BLOCK in
the bitcode.

Differential Revision: https://reviews.llvm.org/D21723

llvm-svn: 307722

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Bitcode: Include any strings added to the string table in the module hash.

Differential Revision: https://reviews.llvm.org/D35037

llvm-svn: 307286

Bitcode: Write the irsymtab to disk.

Differential Revision: https://reviews.llvm.org/D33973

llvm-svn: 306487

[cfi] CFI-ICall for ThinLTO.

Implement ControlFlowIntegrity for indirect function calls in ThinLTO.
Design follows the RFC in llvm-dev, see
https://groups.google.com/d/msg/llvm-dev/MgUlaphu4Qc/kywu0

[cfi] CFI-ICall for ThinLTO.

Implement ControlFlowIntegrity for indirect function calls in ThinLTO.
Design follows the RFC in llvm-dev, see
https://groups.google.com/d/msg/llvm-dev/MgUlaphu4Qc/kywu0AqjAQAJ

llvm-svn: 305533

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Align definition of DW_OP_plus with DWARF spec [3/3]

Summary:
This patch is part of 3 patches that together form a single patch, but must be introduced in stages in order not to break things.

The

Align definition of DW_OP_plus with DWARF spec [3/3]

Summary:
This patch is part of 3 patches that together form a single patch, but must be introduced in stages in order not to break things.

The way that LLVM interprets DW_OP_plus in DIExpression nodes is basically that of the DW_OP_plus_uconst operator since LLVM expects an unsigned constant operand. This unnecessarily restricts the DW_OP_plus operator, preventing it from being used to describe the evaluation of runtime values on the expression stack. These patches try to align the semantics of DW_OP_plus and DW_OP_minus with that of the DWARF definition, which pops two elements off the expression stack, performs the operation and pushes the result back on the stack.

This is done in three stages:
• The first patch (LLVM) adds support for DW_OP_plus_uconst.
• The second patch (Clang) contains changes all its uses from DW_OP_plus to DW_OP_plus_uconst.
• The third patch (LLVM) changes the semantics of DW_OP_plus and DW_OP_minus to be in line with its DWARF meaning. This patch includes the bitcode upgrade from legacy DIExpressions.

Patch by Sander de Smalen.

Reviewers: echristo, pcc, aprantl

Reviewed By: aprantl

Subscribers: fhahn, javed.absar, aprantl, llvm-commits

Differential Revision: https://reviews.llvm.org/D33894

llvm-svn: 305386

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Write summaries for merged modules when splitting modules for ThinLTO.

This is to prepare to allow for dead stripping of globals in the
merged modules.

Differential Revision: https://reviews.llvm.o

Write summaries for merged modules when splitting modules for ThinLTO.

This is to prepare to allow for dead stripping of globals in the
merged modules.

Differential Revision: https://reviews.llvm.org/D33921

llvm-svn: 305027

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BitcodeWriter: Removing unnecessary std::function in favor of template

More cleanup from post-commit discussion on r304516

llvm-svn: 304579

Tidy up a bit of r304516, use SmallVector::assign rather than for loop

This might give a few better opportunities to optimize these to memcpy
rather than loops - also a few minor cleanups (StringRef

Tidy up a bit of r304516, use SmallVector::assign rather than for loop

This might give a few better opportunities to optimize these to memcpy
rather than loops - also a few minor cleanups (StringRef-izing,
templating (to avoid std::function indirection), etc).

The SmallVector::assign(iter, iter) could be improved with the use of
SFINAE, but the (iter, iter) ctor and append(iter, iter) need it to and
don't have it - so, workaround it for now rather than bothering with the
added complexity.

(also, as noted in the added FIXME, these assign ops could potentially
be optimized better at least for non-trivially-copyable types)

llvm-svn: 304566

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[ThinLTO] Efficiency improvement when writing module path string table

Summary:
When writing the combined index, we are walking the entire module
path StringMap in the full index, and checking wheth

[ThinLTO] Efficiency improvement when writing module path string table

Summary:
When writing the combined index, we are walking the entire module
path StringMap in the full index, and checking whether each one should be
included in the index being written. For distributed backends, where we
write an individual combined index for each file, each with only a few
module paths, this is incredibly inefficient. Add a method that takes
a callback and hides the details of whether we are writing the full
combined index, or just a slice, and in the latter case it walks the set
of modules to include instead of the entire index.

For a huge application with around 23K files (i.e. where we were iterating
through the 23K-entry modulePath StringMap 23K times), this change improved
the thin link time by a whopping 48%.

Reviewers: pcc

Subscribers: Prazek, inglorion, llvm-commits

Differential Revision: https://reviews.llvm.org/D33813

llvm-svn: 304516

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(NFC) Track global summary liveness in GVFlags.

Replace GVFlags::LiveRoot with GVFlags::Live and use that instead of
all the DeadSymbols sets. This is refactoring in order to make
liveness informati

(NFC) Track global summary liveness in GVFlags.

Replace GVFlags::LiveRoot with GVFlags::Live and use that instead of
all the DeadSymbols sets. This is refactoring in order to make
liveness information available in the RegularLTO pipeline.

llvm-svn: 304466

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[ThinLTO] Reduce unnecessary map lookups during combined summary write

Summary:
Don't assign values to undefined references, simply don't emit those
reference edges as they are not useful (we were a

[ThinLTO] Reduce unnecessary map lookups during combined summary write

Summary:
Don't assign values to undefined references, simply don't emit those
reference edges as they are not useful (we were already not emitting
call edges to undefined refs).

Also, streamline the later lookup of value ids when writing the
summaries, by combining the check for value id existence with the access
of that value id.

Reviewers: pcc

Subscribers: Prazek, llvm-commits, inglorion

Differential Revision: https://reviews.llvm.org/D33634

llvm-svn: 304323

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Bitcode: Remove some dead code. Spotted by Teresa.

Differential Revision: https://reviews.llvm.org/D33609

llvm-svn: 304046

[IR] Switch AttributeList to use an array for O(1) access

Summary:
Before this change, AttributeLists stored a pair of index and
AttributeSet. This is memory efficient if most arguments do not have

[IR] Switch AttributeList to use an array for O(1) access

Summary:
Before this change, AttributeLists stored a pair of index and
AttributeSet. This is memory efficient if most arguments do not have
attributes. However, it requires doing a search over the pairs to test
an argument or function attribute. Profiling shows that this loop was
0.76% of the time in 'opt -O2' of sqlite3.c, because LLVM constantly
tests values for nullability.

This was worth about 2.5% of mid-level optimization cycles on the
sqlite3 amalgamation. Here are the full perf results:
https://reviews.llvm.org/P7995

Here are just the before and after cycle counts:
```
$ perf stat -r 5 ./opt_before -O2 sqlite3.bc -o /dev/null
13,274,181,184 cycles # 3.047 GHz ( +- 0.28% )
$ perf stat -r 5 ./opt_after -O2 sqlite3.bc -o /dev/null
12,906,927,263 cycles # 3.043 GHz ( +- 0.51% )
```

This patch *does not* change the indices used to query attributes, as
requested by reviewers. Tracking whether an index is usable for array
indexing is a huge pain that affects many of the internal APIs, so it
would be good to come back later and do a cleanup to remove this
internal adjustment.

Reviewers: pete, chandlerc

Subscribers: javed.absar, llvm-commits

Differential Revision: https://reviews.llvm.org/D32819

llvm-svn: 303654

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[IR] Allow attributes with global variables

This patch extends llvm-ir to allow attributes to be set on global variables.
An RFC was sent out earlier by my colleague James Molloy: http://lists.llvm.

[IR] Allow attributes with global variables

This patch extends llvm-ir to allow attributes to be set on global variables.
An RFC was sent out earlier by my colleague James Molloy: http://lists.llvm.org/pipermail/cfe-dev/2017-March/053100.html
A key part of that proposal was to extend LLVM-IR to carry attributes on global variables.
This generic feature could be useful for multiple purposes.
In our present context, it would be useful to carry user specified sections for bss/rodata/data.

Reviewed by: Jonathan Roelofs, Reid Kleckner
Differential Revision: https://reviews.llvm.org/D32009

llvm-svn: 302794

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Re-apply r302108, "IR: Use pointers instead of GUIDs to represent edges in the module summary. NFCI."
with a fix for the clang backend.

llvm-svn: 302176

Revert "IR: Use pointers instead of GUIDs to represent edges in the module summary. NFCI."

This reverts commit r302108. This causes crash in clang bootstrap with LTO.

Contacted the auther in the or

Revert "IR: Use pointers instead of GUIDs to represent edges in the module summary. NFCI."

This reverts commit r302108. This causes crash in clang bootstrap with LTO.

Contacted the auther in the original commit.

llvm-svn: 302140

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IR: Use pointers instead of GUIDs to represent edges in the module summary. NFCI.

When profiling a no-op incremental link of Chromium I found that the functions
computeImportForFunction and computeD

IR: Use pointers instead of GUIDs to represent edges in the module summary. NFCI.

When profiling a no-op incremental link of Chromium I found that the functions
computeImportForFunction and computeDeadSymbols were consuming roughly 10% of
the profile. The goal of this change is to improve the performance of those
functions by changing the map lookups that they were previously doing into
pointer dereferences.

This is achieved by changing the ValueInfo data structure to be a pointer to
an element of the global value map owned by ModuleSummaryIndex, and changing
reference lists in the GlobalValueSummary to hold ValueInfos instead of GUIDs.
This means that a ValueInfo will take a client directly to the summary list
for a given GUID.

Differential Revision: https://reviews.llvm.org/D32471

llvm-svn: 302108

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Bitcode: Simplify how we enumerate summaries in the index. NFCI.

Instead of defining a custom iterator class, just use a function with a
callback, which is much easier to understand and less error p

Bitcode: Simplify how we enumerate summaries in the index. NFCI.

Instead of defining a custom iterator class, just use a function with a
callback, which is much easier to understand and less error prone.

Differential Revision: https://reviews.llvm.org/D32470

llvm-svn: 301942

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Remove line and file from DINamespace.

Fixes the issue highlighted in
http://lists.llvm.org/pipermail/cfe-dev/2014-June/037500.html.

The DW_AT_decl_file and DW_AT_decl_line attributes on namespaces

Remove line and file from DINamespace.

Fixes the issue highlighted in
http://lists.llvm.org/pipermail/cfe-dev/2014-June/037500.html.

The DW_AT_decl_file and DW_AT_decl_line attributes on namespaces can
prevent LLVM from uniquing types that are in the same namespace. They
also don't carry any meaningful information.

rdar://problem/17484998
Differential Revision: https://reviews.llvm.org/D32648

llvm-svn: 301706

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Add speculatable function attribute

This attribute tells the optimizer that the function may be speculated.

Patch by Tom Stellard

llvm-svn: 301680

Add support for DW_TAG_thrown_type.

For Swift we would like to be able to encode the error types that a
function may throw, so the debugger can display them alongside the
function's return value whe

Add support for DW_TAG_thrown_type.

For Swift we would like to be able to encode the error types that a
function may throw, so the debugger can display them alongside the
function's return value when finish-ing a function.

DWARF defines DW_TAG_thrown_type (intended to be used for C++ throw()
declarations) that is a perfect fit for this purpose. This patch wires
up support for DW_TAG_thrown_type in LLVM by adding a list of thrown
types to DISubprogram.

To offset the cost of the extra pointer, there is a follow-up patch
that turns DISubprogram into a variable-length node.

rdar://problem/29481673

Differential Revision: https://reviews.llvm.org/D32559

llvm-svn: 301489

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Make getSlotAttributes return an AttributeSet instead of a wrapper list

Remove the temporary, poorly named getSlotSet method which did the same
thing. Also remove getSlotNode, which is a hold-over f

Make getSlotAttributes return an AttributeSet instead of a wrapper list

Remove the temporary, poorly named getSlotSet method which did the same
thing. Also remove getSlotNode, which is a hold-over from when we were
dealing with AttributeSetNode* instead of AttributeSet.

llvm-svn: 301267

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